Highlights of this issue

Childhood predictors of smoking in adolescence

Figure. Photo by: Barb Sibbald

The smoking rate among adolescents in the context of anti-smoking campaigns is troubling. Predictors of teenage smoking that are commonly cited are parental smoking during childhood, peer pressure during adolescence, and larger lung volumes. Becklake and colleagues investigated these and other possible predictors of teenage cigarette smoking and found that salivary cotinine, a measure of uptake of environmental tobacco smoke, was a significant predictor. It is possible that efficient absorption in childhood of nicotine from second-hand tobacco smoke renders adolescents susceptible to nicotine-seeking behaviour. In a related commentary, Anthonisen and Murray wonder whether such findings mean that future anti-smoking interventions will be directed at susceptible subpopulations rather than the population at large.

The risk of waiting for coronary artery bypass graft surgery

Because the relative urgency of coronary artery bypass graft surgery is still under debate, Légaré and colleagues decided to evaluate safety among patients with stenosis of the left main coronary artery. They assigned 561 such patients to 1 of 4 waiting queues: emergent (no waiting), in-hospital urgent and out-of-hospital semi-urgent A and semi-urgent B (the longest wait). The authors found that pre- and postoperative mortality and morbidity were not significantly associated with the waiting period but point out that the “acceptable” rate of adverse events for a managed waiting strategy is still undetermined. In a related commentary, Rexius asks whether patients do in fact have an increased risk of death on the waiting list and encourages short waiting times to reduce possible risk.

Spectrum of disease and diagnostic tests: tips for EBM learners

Clinicians need to pay close attention to the populations enrolled in studies of diagnostic test performances before they apply the results of those studies to their own patients. In the fifth article of our series on evidence-based medicine, Montori and colleagues present tips and examples of how test performance varies with the spectrum of disease, why disease prevalence does not affect sensitivity, specificity or likelihood ratios, and how the predictive value of a test corresponds with post-test probability of disease.

In Synopsis

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Bernstein discusses ethical requirements about conflict of interest recently imposed by the US federal government on the NIH and the implications for Canadian health research (page 353). Secko reviews new research on endogenous cannabinoids that provide stress-induced analgesia (page 357). Weir looks at public health strategies to prevent stroke (page 363), and Bhandari and colleagues review a study examining the benefits of spinal fusion surgery over intensive rehabilitation for chronic low-back pain (page 365). De Giorgi and colleagues describe the cause of a rapidly growing lesion of the soft palate (page 367), and Ma and colleagues present a case of non-islet cell tumour hypoglycemia (page 359).